Floor squeaks have long been a problem, with attempted solutions offered to date being more symptom relief approaches, rather than addressing the underlying problem. Flexion of floor joists is typically the problem. Even though joists utilized meet code requirements, they are typically not strong enough to provide quiet and stable floors. Another issue is that existing wiring and plumbing installed through and around floor joists make adding extra joists impossible. Adding more wood to existing joists does not substantially increase joist stiffness and requires not only considerable effort but also the space needed to do so. Further, floor joists typically exist in limited space environments not conducive to additional materials or working freedom. Obstacles such as heating ducts, plumbing, wiring, and the like further hinder joist access. Bonding a floor or sub-floor to the joists below can often prevent squeaks but does nothing to prevent joists flexion. Additionally, bonding floors or sub-floors to the joists below requires invasion of the members. Invasion is especially undesirable or even practically impossible when floor covering is already applied to flooring. What is needed is a floor squeak eliminator and floor joist stiffening apparatus that is compact, lightweight and easy to install, with basic pre-tensioning capability for increasing the stiffness of a joist, thereby preventing joist flexion and floor movement. Further, the apparatus should rely on stiffening each joist individually, and not require the recruitment of surrounding joists or structures.